For 100 ft, The main thing you need to look for is a cord that's uses number 8 wire. some 50 ft cords use number 12 or 10. Going 100 ft you need number 8 to keep from having a severe voltage drop at the end of 100 ft.
100 ft of number 8 cord will be a load to handle. If you need to hook and unhook frequently and roll the cord up, you probably will want to buy two 50 ft cords with number 8 wire. You can go to lowes and home depot and buy two sections of wire and make your own... very simple.

* This post was
edited 07/08/08 10:38am by JFG *

Fred

Posted By: 100ton
on 07/08/08 10:53am

As stated above, you are going to get some serious voltage drop with 100' if cord.

Scroll to the bottom of the page to determine wire size VS voltage drop.

Robert

Posted By: time2roll
on 07/08/08 10:24am

Places have sales periodically for $50 for the 50'. If you need 100' often I would make my own to avoid the center connection. 100' premade cord with #12 or #10 wire can be had at Lowes Home Depot etc but does not have the 30 amp connectors.

Someone had posted they saw them at a Harbor Freight retail store for a great price.

I bought a 10/3 100' extension cord from Home Depot and wired it directly to the trailer. I shortened it to 95' after finding an electrical site that showed a 10/3 cord could span 96' and still be within range. I have used this set up for 5 years on two trailers and everything works fine. The cord is yellow and it cost about $85 five years ago.

I have a 50' run of wire to the outlet the I plug the TT in to then I have a 25' cord. So I guess it would no different than me having a 50' cord. Go to home depot and by some 6ga wire if possible and the connectors. You will need a three wire cord. If you can only buy a 4 wire cord buy it and don't use the fourth wire.

Although I agree it's not "advisable", I did it, and the results have been surprisingly good.

First of all, check Camping World and PPL. Both have occassional $50 sales on the 50-ft 10/3 (30-amp) extension cord. This is the cheapest I have found. To make my own single 100-ft 10/3 was above $200 and to make a 100-ft 8/3 was out of this world, as I recall. Two 50's were MUCH cheaper.

I cut the female plug off one cord and hardwired it into my breaker box. I had a 30-ft 10/3 there originally, hardwired. Now, I have 50-ft right off, and when I wish, I can connect the second 50-ft 10/3 cord. Now for the results.

With a 3000-watt steady load, and a 100-ft connection to my generator, which puts out 125+ volts, I am showing 116 volts or better at my kill-a-watt. Also, reading from the panel of my Prosine 2.0, which passes ALL power through it, I am showing 119 volts with this load. I have 2 20-amp runs in my TT, and I suppose the 116-volt reading reflects the more heavily used leg, while the 119-volt reading reflects the true voltage drop over the 100-ft run. Or maybe they just disagree.

This roughly jives with the voltage drop calculators I found on the net. Ideally, a 5% drop is the maximum, and I'm just skirting that under the heaviest loads. To the plus side, the generator is putting out 5 additional volts of headroom, which I'm GUESSING can provide a buffer (oh, I'm going to hear about that).

Also, bear in mind that the heaviest loads are intermittent. Moderate loads do not pull the voltage down nearly so much.

I don't recommend this, because I have NO expertise in this. The experts have all advised you against this, many of whom are practicing electricians. However, AFAICT, the results are not alarming from a safety standpoint.

Or are they?

Posted By: Bumpyroad
on 07/09/08 05:58am

I sort of think that if I was making them myself, I would make a 60 ft and a 40 ft instead of 2 50s.
bumpy

Posted By: Jet Dr.
on 07/08/08 08:08pm

You may be better off to buy 100' of 8/2 outdoor wire, UFB is best. you can buy the connectors for the ends. Most RV ext cords will be 10 or smaller unless you get a 50 amp cord and use an adapter to plug into a 30 amp plug.